Affiliation

Abstract

Aims:
To determine if indirect testing for bronchial hyperresponsiveness (BHR) to monitor inhaled corticosteroid (ICS) treatment in asthma is feasible and acceptable in primary care.

Methods:
Fourteen adult patients with asthma aged 22-70 years (4M:10F, forced expiratory volume in 1 s >70% predicted) taking ICS performed a test for BHR using mannitol on three visits 6 weeks apart. ICS dose adjustments were made based on the presence of BHR. The Asthma Quality of Life Questionnaire (AQLQ) and the Asthma Control Questionnaire were used at each visit. A semi structured interview at study exit assessed subject acceptability.

Results:
BHR did not return in those with no BHR at study entry (n=9) with decreasing ICS dose. Improvements in BHR with increasing ICS dose (n=5) were observed with clinically significant improvements in AQLQ (mean score increase >0.5, p=0.02). Feasibility and acceptability of BHR testing was demonstrated.

Conclusions:
It is feasible and acceptable to perform BHR testing using mannitol to help identify patients with asthma who would benefit from ICS dose increases and those with no BHR who could have a dose reduction.

Conflict of interest statement

JAT holds shares in Pharmaxis Ltd. NJG has no conflict of interest. JDB receives royalties from the sale of Aridol™/Osmohale™, holds shares in Pharmaxis Ltd, and has acted as a consultant to Pharmaxis Ltd.

Figure 2. Mean and standard error of the doses of inhaled corticosteroid (fluticasone equivalents = μg) and long-acting β2-agonist (pooled doses = μg) at each study visit over 12 weeks for subjects without bronchial hyperresponsiveness (BHR) to mannitol (n=9) and those with BHR (n=5) at the beginning of the study. *p<0.05, **p<0.01, ***p<0.001.